US20150042891A1 - Illumination apparatus, and liquid crystal display apparatus and television receiver apparatus provided with same - Google Patents
Illumination apparatus, and liquid crystal display apparatus and television receiver apparatus provided with same Download PDFInfo
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- US20150042891A1 US20150042891A1 US14/375,216 US201314375216A US2015042891A1 US 20150042891 A1 US20150042891 A1 US 20150042891A1 US 201314375216 A US201314375216 A US 201314375216A US 2015042891 A1 US2015042891 A1 US 2015042891A1
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- United States
- Prior art keywords
- light
- light sources
- illumination device
- leds
- diffusion
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- F21V13/00—Producing particular characteristics or distribution of the light emitted by means of a combination of elements specified in two or more of main groups F21V1/00 - F21V11/00
- F21V13/02—Combinations of only two kinds of elements
- F21V13/04—Combinations of only two kinds of elements the elements being reflectors and refractors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- F21V5/00—Refractors for light sources
- F21V5/04—Refractors for light sources of lens shape
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133603—Direct backlight with LEDs
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133611—Direct backlight including means for improving the brightness uniformity
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
-
- F21Y2101/02—
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
- F21Y2115/00—Light-generating elements of semiconductor light sources
- F21Y2115/10—Light-emitting diodes [LED]
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members
- G02F1/133607—Direct backlight including a specially adapted diffusing, scattering or light controlling members the light controlling member including light directing or refracting elements, e.g. prisms or lenses
Definitions
- the present invention relates to an illumination device that uses an LED as a light source, for example.
- the present invention further relates to a liquid crystal display device and a television receiver provided with this illumination device.
- Fluorescent lamp illumination devices have traditionally been widely used in households, offices, and the like. Cold cathode fluorescent lamp illumination devices have also been used for liquid crystal display devices and television receivers.
- An ordinary fluorescent lamp such as a cold cathode fluorescent lamp is a light source in which an electrode is placed inside a glass tube where a prescribed gas has been sealed, and ultraviolet rays generated by electrical discharge are converted to visible light by hitting fluorescent material coated on the inner surface of this glass tube.
- the illumination apparatus disclosed in Patent Document 1 has individual LED lenses that are elliptical in a cross-sectional view respectively provided on the light illumination side of a plurality of LEDs that are in a loop shape.
- the long axes of the respective LED lenses face the center of this loop shape. Accordingly, this conventional illumination apparatus widely emits light towards the center and the outside of this loop shape and has a uniform brightness.
- Patent Document 1 Japanese Patent Application Laid-Open Publication No. 2012-4035
- Patent Document 1 The conventional illumination device disclosed in Patent Document 1, however, requires a large number of LED lenses in order to evenly illuminate a wide area. This adds to the number of components and assembly steps, and leads to an increase in cost of the illumination device. There is also a risk that uneven brightness could occur between adjacent LED lenses.
- the present invention was made in view of the above-mentioned points and aims at providing an illumination device that can lower costs, improve the usage efficiency of light, and reduce uneven brightness.
- the present invention further aims at providing a liquid crystal display device and a television receiver provided with this illumination device.
- an illumination device of the present invention includes a plurality of light sources arranged in a row; and a diffusion lens that is disposed on a light-emitting side of the light sources in order to diffuse light emitted by the light sources and that extends in an arrangement direction of the plurality of light sources, the diffusion lens being shared by the respective light sources, wherein a degree of light diffusion of the diffusion lens towards a right angle to the arrangement direction of the plurality of light sources is larger than the degree of light diffusion towards the array direction of the plurality of light sources.
- the illumination device has the single diffusion lens for diffusing the light emitted from the respective plurality of light sources.
- the number of diffusion lenses in relation to the number of light sources is greatly reduced.
- the diffusion lens is also present between the adjacent light sources. Accordingly, uneven brightness that could occur between the adjacent light sources is suppressed.
- the diffusion lens has a housing recess that covers and houses the light sources, and a curved surface that faces the housing recess and substantially protrudes outwards along a light-emitting direction of the light sources, and in a cross-section at a right angle to the array direction of the plurality of light sources, the curved surface has substantially arced sections that protrude outwards, the substantially arced sections being respectively formed at two spots on the left and the right of a central axis line that extends in a direction normal to an emitting surface of the light sources.
- the light emitted by the light sources refracts at the curved surface of the housing recess of the diffusion lens, passes through the diffusion lens, and then refracts again at the curved surface.
- the light is widely diffused by the curved surface via the substantially arced sections.
- the degree of light diffusion of the diffusion lens in the direction forming a right angle with the array direction of the plurality of light sources becomes relatively high.
- the two substantially arced sections of the curved surface both have centers of curvature at locations that are equidistant from the emitting surface of the light sources and equidistant from the central axis extending in the direction normal to the emitting surface of the light sources, the substantially arced sections having the same radius.
- the illumination device emits light in similar directions on both sides of the plane extending in the array direction of the plurality of light sources, in addition to the central axis (optical axis) that extends in the direction normal to the emitting surface of the light sources. Accordingly, the illumination device can uniformly illuminate the periphery of the light sources and the diffusion lens.
- the two substantially arced sections of the curved surface both have centers of curvature that are different distances from the emitting surface of the light sources and/or different distances from the central axis extending in the direction normal to the emitting surface of the light sources.
- the illumination device emits light in different directions on both sides of the plane extending in the array direction of the plurality of light sources, in addition to the central axis (optical axis) that extends in the direction normal to the emitting surface of the light sources. Accordingly, the differing brightness among both sides of the light sources and diffusion lens is useful at desired times.
- the diffusion lens has a stray light recess that is adjacent to the housing recess and that faces the curved surface, the stray light recess receding towards the curved surface.
- a diffusion cover that diffuses light exiting from the diffusion lens is disposed on a light-exiting side of the diffusion lens.
- the light emitted by the diffusion lens of the illumination device can be further diffused and illuminate a room, for example. Accordingly, the usage efficiency of light of the illumination device is improved.
- a reflective sheet that reflects light emitted by the light sources is disposed on a side of the light sources opposite to the light-emitting side, the reflective sheet facing the light-emitting side of the light sources.
- the plurality of light sources are arranged in a circular shape, and the diffusion lens has a ring shape.
- the plurality of light sources are arranged in a straight line, and the diffusion lens has a bar shape.
- each of the pairs having the plurality of light sources and the diffusion lens that is shared among the plurality of light sources.
- the pairs of the plurality of light sources and the respective diffusion lenses is arranged in the direction at a right angle to the array direction of the plurality of light sources.
- the present invention includes a liquid crystal display device and a television receiver having the illumination device with the configuration described above. With this configuration, the number of diffusion lenses to the number of light sources is greatly reduced in the liquid crystal display device and the television receiver, and uneven brightness is suppressed.
- an illumination device that can decrease costs, improve the usage efficiency of light, and reduce uneven brightness can be provided.
- this illumination device it is possible to provide a liquid crystal display device and a television receiver that can lower costs and suitably display images and the like.
- FIG. 1 is a complete perspective view of an illumination device of Embodiment 1 of the present invention as seen from below.
- FIG. 2 is a vertical cross-sectional view of a portion of the illumination device according to Embodiment 1 of the present invention.
- FIG. 3 is a bottom view of the illumination device according to Embodiment 1 of the present invention when a diffusion cover has been removed.
- FIG. 4 is a magnified bottom view of a portion of the illumination device according to Embodiment 1 of the present invention when the diffusion cover has been removed.
- FIG. 5 is a magnified bottom view of the illumination device according to Embodiment 1 of the present invention when the diffusion cover and diffusion lens have been removed.
- FIG. 6 is a vertical cross-sectional view where a portion of the LED and diffusion lens of the illumination device of Embodiment 1 of the present invention has been magnified.
- FIG. 7 is a vertical cross-sectional view where a portion of an LED and diffusion lens of the illumination device of Embodiment 2 of the present invention has been magnified.
- FIG. 8 is a vertical cross-sectional view where a portion of an LED and diffusion lens of the illumination device of Embodiment 3 of the present invention has been magnified.
- FIG. 9 is a bottom view of an illumination device according to Embodiment 4 when a diffusion cover has been removed.
- FIG. 10 is a bottom view of an illumination device according to Embodiment 5 when a diffusion cover has been removed.
- FIG. 11 is a front view of a television receiver according to Embodiment 6 of the present invention.
- FIG. 12 is a horizontal top cross-sectional view of the television receiver according to Embodiment 6 of the present invention.
- FIG. 13 is an exploded perspective view of a liquid crystal display device in the television receiver according to Embodiment 6 of the present invention.
- Embodiments of the present invention will be described below with reference to FIGS. 1 to 13 .
- An illumination device (indoor illumination apparatus) of Embodiments 1 to 5 in which an indoor ceiling surface serves as the installation surface, and an illumination device (backlight) for use with a liquid crystal display device of Embodiment 6 will be described as examples.
- FIG. 1 is a complete perspective view from below the illumination device
- FIG. 2 is a vertical cross-sectional view of a portion of the illumination device
- FIG. 3 is a bottom view of the illumination device when a diffusion cover has been removed.
- an illumination device 1 has a relatively thin disk shape that completely extends along an installation surface (ceiling surface).
- the illumination device 1 includes a base member 2 , a diffusion cover 3 , substrates 4 , LEDs 5 that are the light source, a diffusion lens 6 , and a reflective sheet 7 .
- the base member 2 is arranged above the illumination device 1 in the vicinity of the ceiling surface, which is the installation surface of the illumination device 1 .
- the base member 2 has a round plate shape that faces downwards, the base member 2 having a diameter D1 of 600 mm, for example.
- the inside of the base member 2 holds the substrates 4 on which the respective LEDs 5 are mounted, the diffusion lens 6 , and the reflective sheet 7 .
- a power supply connector (not shown) is connected through the radial center of the base member 2 . This power supply connector supplies power to the LEDs 5 .
- a projection 2 a that projects downward is disposed in the center of the base member 2 .
- the tip of the projection 2 a has a diameter D2 of 200 mm, for example, and is near the inner surface center of the diffusion cover 3 .
- a control section that has a power supply circuit, a control circuit, and the like (not shown) is disposed inside the projection 2 a , and this control section is electrically connected to the power supply connector and the LEDs 5 .
- the diffusion cover 3 is arranged on the bottom of the illumination device 1 and faces downward towards the room, which is the target for illumination of the illumination device 1 .
- the diffusion cover 3 has a circular shape with a diameter that is substantially the same as the outer diameter of the base member 2 .
- the diffusion cover 3 fits into and is held by the periphery of the base member 2 , and covers the entire surface of the base member 2 from below.
- the diffusion cover 3 is a PMMA (polymethyl methacrylate) resin with a diffusing material mixed in, for example, but may be a PC (polycarbonate resin), a PS (polystyrene) resin, or a PP (polypropylene) resin.
- the diffusion cover 3 is arranged on the light-emitting side of the diffusion lens 6 in order to diffuse light exiting the diffusion lens 6 .
- the bottom surface of the diffusion cover 3 emits this light.
- the substrates 4 have a substantially rectangular shape in a plan view and are attached to the bottom of the base member 2 .
- the LED 5 is a white LED (light-emitting diode) that emits white light, for example, and a plurality of these LEDs 5 are mounted on the bottom surface of the respective substrates 4 .
- the plurality of LEDs 5 are supplied with power through the power source connector and the control section, and radiate light towards the diffusion cover 3 below.
- the diffusion lens 6 is arranged so as to cover the bottoms of the respective LEDs 5 in order to diffuse the light emitted by the LEDs 5 .
- the diffusion lens 6 has a single ring shape in order to completely cover the plurality of LEDs 5 .
- the reflective sheet 7 is arranged above the LEDs 5 and below the substrates 4 .
- the reflective sheet 7 is a sheet member having a substantially donut shape that covers the area from the outer radial side of the projection 2 a of the base member 2 to the periphery of the base member 2 . The portions corresponding to the LEDs 5 and substrates 4 are cut out.
- the reflective sheet 7 is a white PET foam (polyethylene terephthalate), for example. Light from the LEDs 5 that hits the inner surface of the diffusion cover 3 and reaches the base member 2 side is reflected by the reflective sheet 7 back towards the emitting side of the LEDs 5 , for example.
- a highly reflective surface may be formed by coating a silver material or the like on the bottom surface of the base member 2 , for example, or a highly reflective surface may be formed by applying a mirror finish or the like on the bottom surface of the base member 2 .
- FIG. 4 is a magnified bottom view of a portion of the illumination device 1 when the diffusion cover 3 has been removed
- FIG. 5 is a magnified bottom view of the illumination device 1 when the diffusion cover 3 and diffusion lens 6 have been removed
- FIG. 6 is a vertical cross-sectional view where a portion of the LEDs 5 and the diffusion lens 6 has been magnified.
- the depiction of the reflective sheet 7 has been omitted.
- the left shows the outer radial side (periphery) of the illumination device 1
- the right shows the inner radial side (center) of the illumination device 1 .
- the eight substrates 4 are arranged so as to form a substantially circular shape with the central axis of the circular base member 2 as the center, or more specifically, so as to form a regular octagon, for example.
- the eight substrates 4 each hold five LEDs 5 , for example.
- Approximately 40 of the LEDs 5 are arranged in a row so as to form a circular shape having the central axis of the circular base member 2 as the center thereof.
- the arrangement circle of the plurality of LEDs 5 has a diameter D3 (see FIG. 5 ) of 420 mm, for example.
- a radial distance X from the periphery of the projection 2 a to the periphery of the base member 2 is 200 mm
- a radial distance Y from the periphery of the projection 2 a to the arrangement circle of the LEDs 5 is 110 mm
- a radial distance Z from the arrangement circle of the LEDs 5 to the periphery of the base member 2 is 90 mm. This results in a relation of distance Y>distance Z.
- a gap L in the peripheral direction of LEDs 5 that are adjacent, among the respective plurality of LEDs 5 (see FIG. 5 ), is 33 mm, for example.
- a distance H (see FIG. 2 ) from the substrates 4 to the diffusion cover 3 is set to be 26 mm, for example.
- the illumination device 1 is configured such that the gap L between the adjacent LEDs 5 and the distance H from the substrates 4 to the diffusion cover 3 is L/H ⁇ 1.3, for example.
- the diffusion lens 6 is arranged on the light-emitting side of the LEDs 5 and completely covers the LEDs 5 .
- the diffusion lens 6 has a ring shape that extends in accordance with the array direction of the plurality of LEDs 5 .
- the diffusion lens 6 is shared among the plurality of LEDs 5 .
- the diffusion lens 6 is a PMMA (polymethyl methacrylate) resin with a diffusing material mixed in, for example, but may be a PC (polycarbonate resin), or a PS (polystyrene) resin.
- the diffusion lens 6 has a housing recess 6 a in the top thereof.
- the housing recess 6 a has a size and shape that covers and houses all of the LEDs 5 together, and is formed in a looped trench shape, the central axis of which coincides with the diffusion lens 6 .
- the vertical cross-section of the housing recess 6 a which is parallel to the radial direction thereof, has a substantially parabolic shape or a substantially “U” shape that recedes downward from the top of the diffusion lens 6 .
- the bottom of the diffusion lens 6 is a curved surface 6 b disposed on the outside of the emitting direction of the LEDs 5 .
- the curved surface 6 b faces the housing recess 6 a , and as shown in FIG. 6 the vertical cross-section parallel to the radial direction substantially protrudes towards the outside of the emitting direction of the LEDs 5 .
- the curved surface 6 b is formed as a looped projection, the central axis of which coincides with the diffusion lens 6 .
- the curved surface 6 b of the diffusion lens 6 has two substantially arced sections 6 c and 6 d that protrude towards the outside of the emitting direction of the LEDs 5 .
- the substantially arced sections 6 c and 6 d are respectively formed on the left and right of a central axis CL (optical axis) that extends in a direction normal to an emitting surface 5 a of the LEDs 5 .
- the periphery of the central axis CL which is between the substantially arced sections 6 c and 6 d of the curved surface 6 b , recedes towards the LEDs 5 .
- the light emitted by the LEDs 5 refracts at the curved surface of the housing recess 6 a of the diffusion lens 6 , passes through the diffusion lens 6 , and refracts again at the curved surface 6 b .
- the light is widely diffused through the substantially arced sections 6 c and 6 d .
- the degree of light diffusion of the diffusion lens 6 in the direction forming a right angle with the array direction of the plurality of LEDs 5 can be made comparatively high.
- the illumination device 1 includes the plurality of LEDs 5 arranged in a row in a circular shape, and the diffusion lens 6 that extends in a ring shape in accordance with the array direction of the plurality of LEDs 5 and that is shared by the plurality of LEDs 5 .
- the diffusion lens 6 has a degree of light diffusion in a direction (the direction parallel to the radial direction) at a right angle to the array direction of the plurality of LEDs 5 that is high compared to the degree of light diffusion in the array direction of the plurality of LEDs 5 .
- the illumination device 1 has the single diffusion lens 6 for diffusing the light emitted from the plurality of LEDs 5 .
- the number of the diffusion lenses 6 with respect to the number of the LEDs 5 can be greatly reduced.
- the diffusion lens 6 is also present between the adjacent LEDs 5 . Accordingly, it is possible to suppress uneven brightness that could occur between the adjacent LEDs 5 .
- the substantially arced section 6 c of the curved surface 6 b has a radius R1 extending to a center of curvature CP1, which is a distance U1 from the emitting surface 5 a of the LEDs 5 and a distance W1 from the central axis CL (optical axis) extending in the direction normal to the emitting surface 5 a of the LEDs 5 .
- the substantially arced section 6 d of the curved surface 6 b has a radius R2 extending to a center of curvature CP2, which is a distance U2 from the emitting surface 5 a of the LEDs 5 and a distance W2 from the central axis CL (optical axis) extending in the direction normal to the emitting surface 5 a of the LEDs 5 .
- the distance U1 is equal to the distance U2
- the distance W1 is equal to the distance W1
- the radius R1 is equal to the radius R2.
- the two substantially arced sections 6 c and 6 d of the curved surface 6 b respectively have the centers of curvature CP1 and CP2 that are at the equal distances U1 and U2 from the emitting surface 5 a of the LEDs 5 and at the equal distances W1 and W2 from the central axis CL (optical axis) extending in the direction normal to the emitting surface 5 a of the LEDs 5 .
- the radii R1 and R2 from the respective substantially arced sections 6 c and 6 d to the centers of curvature CP1 and CP2 are equal to each other.
- the illumination device 1 can emit light in similar directions on both sides of the plane extending in the array direction of the plurality of LEDs 5 , in addition to the central axis CL (optical axis) that extends in the direction normal to the emitting surface 5 a of the LEDs 5 . Accordingly, the illumination device 1 can evenly illuminate the periphery of the LEDs 5 and the diffusion lens 6 .
- the illumination device 1 has the diffusion cover 3 that diffuses the light emitted from the diffusion lens 6 arranged on the light-emitting side of the diffusion lens 6 ; therefore, the light emitted by the diffusion lens 6 can be further diffused and illuminate a room, for example. Accordingly, the usage efficiency of light of the illumination device 1 can be improved.
- the illumination device 1 also has the reflective sheet 7 , which reflects light emitted by the LEDs 5 , arranged on the side opposite to the light emitting side of the LEDs 5 ; thus, light from the LEDs 5 that hits the diffusion cover 3 and reaches the side opposite to the light-emitting side of the LEDs 5 is reflected by the reflective sheet 7 back towards the emitting side of the LEDs 5 , for example. Accordingly, the usage efficiency of light of the illumination device 1 can be improved. Furthermore, there is only one of the diffusion lenses 6 , and thus it is possible to improve the workability of installing the reflective sheet 7 .
- a plurality of LEDs 5 are arranged in a circular shape and the diffusion lens 6 forms a ring shape, thereby making it possible to reduce the number of the LEDs 5 and the size of the diffusion lens 6 in the illumination device 1 having a circular shape.
- the illumination device 1 that can decrease costs, improve the usage efficiency of light, and reduce uneven brightness can be provided.
- FIG. 7 is a vertical cross-sectional view where a portion of an LED and diffusion lens of the illumination device have been magnified.
- the left side shows the outer radial side (periphery) of the illumination device
- the right side shows the inner radial side (center) of the illumination device.
- the hatching pattern showing the cross-sectional cut ends of the diffusion lens has been omitted.
- the basic configuration of the present embodiment is the same as that described in Embodiment 1 with reference to FIGS. 1 to 6 , and thus, components in common with Embodiment 1 are assigned the same reference characters, and drawings and descriptions thereof will be omitted.
- the bottom of a diffusion lens 6 has a curved surface 6 e towards the outside in the emitting direction of LEDs 5 .
- the curved surface 6 e of the diffusion lens 6 has two substantially arced sections 6 f and 6 g that protrude towards the outside of the emitting direction of the LEDs 5 .
- the substantially arced section 6 f of the curved surface 6 e has a radius R3 extending to a center of curvature CP3, which is a distance U3 from the emitting surface 5 a of the LEDs 5 and a distance W3 from a central axis CL (optical axis) extending in the direction normal to the emitting surface 5 a of the LEDs 5 .
- the substantially arced section 6 g of the curved surface 6 e has a radius R4 extending to a center of curvature CP4, which is a distance U4 from the emitting surface 5 a of the LEDs 5 and a distance W4 from the central axis CL (optical axis) extending in the direction normal to the emitting surface 5 a of the LEDs 5 .
- the center of curvature CP3 near the substantially arced section 6 f on the outer radial side is slightly closer to the central axis CL and slightly more above the emitting surface 5 a .
- the distance U3 and the distance U4 are different from each other, and the distance W3 and the distance W4 are different from each other.
- the radius R3 and the radius R4 are approximately the same.
- the centers of curvature CP3 and CP4 are located at the distances U3 and U4 where the substantially arced sections 6 f and 6 g both differ from the emitting surface 5 a of the LEDs 5 and at the distances W3 and W4 where the substantially arced sections 6 f and 6 g both differ from the central axis CL (optical axis) that extends in a direction normal to the emitting surface 5 a of the LEDs 5 .
- the illumination device 1 can emit light in different directions on both sides of the plane extending in the array direction of the plurality of LEDs 5 , in addition to the central axis CL (optical axis) that extends in the direction normal to the emitting surface 5 a of the LEDs 5 . Accordingly, the differing brightness among the inner radial direction area and the outer radial direction area of the LEDs 5 and diffusion lens 6 is useful at desired times.
- the curved surface 6 e of the diffusion lens 6 inclines towards the outer radial side; thus, it is possible to illuminate a large area in the outer radial direction as compared to the configuration in
- the diffusion lens 6 is adjacent to the housing recess 6 a and has stray light recesses 6 h in locations facing the curved surface 6 b .
- the stray light recesses 6 h recede towards the curved surface 6 b , in a manner similar to the housing recess 6 a , and are disposed on the inner radial side and outer radial side of the housing recess 6 a .
- stray light SL that could occur due to reflection by the diffusion lens 6 or the like is reflected by the stray light recesses 6 h .
- the stray light SL that reflects at the stray light recesses 6 h can be emitted by being widely diffused through the curved surface 6 b.
- FIG. 8 is a vertical cross-sectional view where a portion of an LED and diffusion lens of the illumination device has been magnified.
- the left side shows the outer radial side (periphery) of the illumination device
- the right side shows the inner radial side (center) of the illumination device.
- the hatching pattern showing the cross-sectional cut ends of the diffusion lens has been omitted.
- the fundamental configuration of this embodiment is the same as Embodiments and 2, and thus, the constituting elements shared with these embodiments will be given the same reference characters, and drawings and detailed explanations thereof will be omitted.
- the bottom of a diffusion lens 6 has a curved surface 6 k on outside of the emitting direction of LEDs 5 .
- the curved surface 6 k of the diffusion lens 6 has two substantially arced sections 6 m and 6 n that protrude towards the outside of the emitting direction of the LED 5 .
- the substantially arced section 6 m of the curved surface 6 k has a radius R5 extending to a center of curvature CP5, which is a distance U5 from an emitting surface 5 a of the LEDs 5 and a distance W5 from a central axis CL (optical axis) extending in the direction normal to the emitting surface 5 a of the LEDs 5 .
- the substantially arced section 6 n of the curved surface 6 e has a radius R6 extending to a center of curvature CP6, which is a distance U6 from the emitting surface 5 a of the LEDs 5 and a distance W6 from the central axis CL (optical axis) extending in the direction normal to the emitting surface 5 a of the LEDs 5 .
- the center of curvature CP5 near the substantially arced section 6 m on the outer radial side is slightly closer to the central axis CL and goes above substrates 4 from the emitting surface 5 a .
- the distance U5 and the distance U6 are different from each other, and the distance W5 and the distance W6 are different from each other.
- the radius R5 is longer than the radius R6.
- the centers of curvature CP5 and CP6 are located at the distances U5 and U6 where the substantially arced sections 6 m and 6 n both differ from the emitting surface 5 a of the LEDs 5 and at the distances W5 and W6 where the substantially arced sections 6 m and 6 n both differ from the central axis CL (optical axis) that extends in a direction normal to the emitting surface 5 a of the LEDs 5 .
- the illumination device 1 emits light in different directions on both sides of the plane extending in the array direction of the plurality of LEDs 5 , in addition to the central axis CL (optical axis) that extends in the direction normal to the emitting surface 5 a of the LEDs 5 . Accordingly, the differing brightness among the inner radial direction area and the outer radial direction area of the LEDs 5 and diffusion lens 6 is useful at desired times.
- the curved surface 6 k of the diffusion lens 6 inclines further towards the outer radial side than in Embodiment 2; thus, it is possible to illuminate a larger area in the outer radial direction as compared to the configuration in Embodiment 2.
- FIG. 9 is a bottom view of the illumination device when a diffusion cover is removed.
- the basic configuration of the present embodiment is the same as that described in Embodiment 1 with reference to FIGS. 1 to 6 , and thus, components in common with Embodiment 1 are assigned the same reference characters, and drawings and descriptions thereof will be omitted.
- An illumination device 1 according to Embodiment 4 is provided with four diffusion lenses 8 , as shown in FIG. 9 .
- the diffusion lenses 8 have an arc shape with a central angle of 90° extending in accordance with the circular array direction of a plurality of LEDs 5 (not shown in FIG. 9 ).
- Each of the diffusion lenses 8 covers a plurality of LEDs 5 across two substrates and is arranged on the light-emitting side of the respective LEDs 5 .
- Each of the diffusion lenses 8 is also used to diffuse light emitted by the respective plurality of LEDs 5 .
- the illumination device 1 can greatly reduce the number of diffusion lenses 8 to the number of the LEDs 5 .
- the dimensional accuracy of the diffusion lenses 8 can be increased by configuring the diffusion lenses 8 in an arc shape and not a ring shape. Accordingly, the usage efficiency of light can be improved.
- FIG. 10 is a bottom view of the illumination device when a diffusion cover is removed.
- the basic configuration of the present embodiment is the same as that described in Embodiment 1 with reference to FIGS. 1 to 6 , and thus, components in common with Embodiment 1 are assigned the same reference characters, and drawings and descriptions thereof will be omitted.
- An illumination device 1 according to Embodiment 5 is provided with eight diffusion lenses 9 , as shown in FIG. 10 .
- the diffusion lenses 9 have an arc shape with a central angle of 45° extending in accordance with the circular array direction of a plurality of LEDs 5 (not shown in FIG. 10 ).
- Each of the diffusion lenses 9 covers the plurality of LEDs 5 across one substrate and is arranged on the light-emitting side of the respective LEDs 5 .
- Each of the diffusion lenses 9 is also used to diffuse light emitted by the respective plurality of LEDs 5 .
- the illumination device 1 can greatly reduce the number of diffusion lenses 9 to the number of the LEDs 5 .
- the dimensional accuracy of the diffusion lenses 9 can be increased by configuring the diffusion lenses 9 in an arc shape and not a ring shape. Accordingly, the usage efficiency of light can be improved.
- FIG. 11 is a front view of the television receiver
- FIG. 12 is a horizontal top cross-sectional view of the television receiver
- FIG. 13 is an exploded perspective view of a liquid crystal display device of the television receiver.
- a television receiver 100 according to Embodiment 6 has a liquid crystal display device 110 that uses liquid crystal for display of images and the like. As shown in FIGS. 11 and 12 , the television receiver 100 has a substantially rectangular shape in a plan view that is longer in the left-and-right direction.
- the television receiver 100 has an external cover 101 that has a flat rectangular box shape.
- the external cover 101 is horizontally long and is supported by an upright stand 102 .
- the external cover 101 includes a front cover 101 F and a rear cover 101 R.
- the front cover 101 F has a so-called frame shape that has a rectangular opening on the front side thereof.
- the rear cover 101 R fits into the front cover 101 F so as to cover the rear side of the front cover 101 F, and this forms the rectangular box-shaped external cover 101 .
- the external cover 101 has a plurality of ventilation holes that penetrate the inside and outside thereof. These ventilation holes make it possible for air to flow freely between the inside and the outside of the external cover 101 .
- the inside of the external cover 101 includes the liquid crystal display device 110 , panel holders 103 , and circuit substrates 104 .
- the liquid crystal display device 110 is a display device that uses liquid crystal to display images and the like, and has a substantially rectangular shape in a plan view that is longer in the left-and-right direction. As shown in FIGS. 12 and 13 , the liquid crystal display device 110 includes a liquid crystal display panel 120 and an illumination device 130 , which is the backlight unit of the liquid crystal display panel 120 .
- the liquid crystal display panel 120 includes an active matrix substrate 121 , a color filter substrate 122 , and polarizing plates 123 .
- the color filter substrate 122 is sometimes simply referred to as an opposite substrate.
- the active matrix substrate 121 is disposed opposite to the color filter substrate 122 disposed on the display surface side of the liquid crystal display panel 120 .
- the active matrix substrate 121 has TFTs (thin-film transistors) made of switching elements, pixel electrodes, and common electrodes on a prescribed surface of the active matrix substrate 121 (not shown).
- the pixel electrodes and the common electrodes are inter-digital electrodes that form pairs.
- the active matrix substrate 121 and the color filter substrate 122 are respectively covered by alignment films (not shown) that have prescribed respective surfaces that orient the liquid crystal in a specific direction.
- the active matrix substrate 121 and the color filter substrate 122 are bonded together by a sealing member (not shown) such that the prescribed surfaces thereof face each other. Liquid crystal is sandwiched between the active matrix substrate 121 and the color filter substrate 122 , and is sealed in the space surrounded by the sealing member.
- the polarizing plates 123 are bonded to prescribed surfaces that are the respective opposite surfaces of the active matrix substrate 121 and the color filter substrate 122 having the liquid crystal sealed therebetween.
- the polarizing plates 123 are sheets through which only light waves oscillating in a specific direction are allowed through, and the two polarizing plates 123 are respectively bonded such that the transmission axes thereof are offset by approximately 90.
- the liquid crystal display panel 120 configured in this manner adjusts the orientation of the liquid crystal by an electric field generated between the pixel electrodes and the common electrodes in the active matrix substrate 121 on the basis of an image signal, thus changing the transmittance of light through the liquid crystal layer.
- the liquid crystal display panel 120 is of a transverse field type as described above, for example, and causes liquid crystal molecules to rotate within a plane parallel to the main substrate surface by generating an electric field parallel to the main surface of the active matrix substrate 121 .
- the illumination device 130 is a backlit unit for illuminating the liquid crystal display panel 120 from below and for generating this illumination light.
- the illumination device 130 is arranged on the rear surface side of the liquid crystal display panel 120 .
- the illumination device 130 includes a chassis 131 , a light-emitting module 140 , a diffusion plate 132 that is equivalent to a diffusion cover, a prism sheet 133 , and a lens sheet 134 .
- the chassis 131 has a box shape that is substantially rectangular in a plan view with an opening on the liquid crystal display panel 120 side (the front side of the television receiver 100 ).
- the chassis 131 houses the light-emitting module 140 therein, or namely, on an inner bottom surface 131 a of the chassis 131 .
- the light-emitting module 140 emits light and is housed inside the chassis 131 .
- the light-emitting module 140 includes substrates 141 , a plurality of LEDs 142 that are the light source, diffusion lenses 143 , and a reflective sheet 144 .
- the substrates 141 have a substantially rectangular shape in a plan view that stretches along the long-side direction of the chassis 131 , and are attached to the inner bottom surface 131 a of the chassis 131 . Three of the substrates 141 are arranged substantially parallel in the short-side direction of the chassis 131 .
- the LEDs 142 are white LEDs (light-emitting diodes) that emit white light, for example, and a plurality thereof are respectively mounted on the three substrates 141 .
- the plurality of LEDs 142 are arranged in a row in parallel so as to form a straight line along the long-side direction of the substrates 141 , which are substantially rectangular in a plan view.
- the plurality of LEDs 142 emit light towards the respective diffusion lenses 143 above.
- the diffusion lenses 143 are respectively provided for the three substrates 141 .
- the diffusion lenses 143 are arranged so as to cover the respective front sides of the LEDs 142 , which are the light-emitting sides, in order to diffuse the light emitted from these LEDs 142 .
- the diffusion lenses 143 In order for the respective diffusion lenses 143 to completely cover the plurality of LEDs 142 mounted on one of the substrates 141 , the diffusion lenses 143 have a bar shape extending along the long-side direction of the chassis 131 and are respectively shared among the plurality of LEDs 142 .
- the detailed configuration of the diffusion lenses 143 in a vertical cross-sectional view is at a right angle to the array direction of the LEDs 142 is similar to the configurations in Embodiments 1 to 3, and therefore, an explanation thereof will be omitted.
- the configuration of the diffusion lenses 143 can be adjusted such that the degree of light diffusion towards the direction forming a right angle with the array direction of the plurality of LEDs 142 (the short-side direction of the chassis 131 ) is larger than the degree of light diffusion towards the array direction of the plurality of LEDs 142 (the long-side direction of the chassis 131 ).
- the reflective sheet 144 is arranged on the rear side of the LEDs 142 , which is the front side of the substrate 141 .
- the reflective sheet 144 is a sheet member that has a rectangular shape in a plan view and that covers the entire inner bottom surface 131 a of the chassis 131 .
- the reflective sheet 144 has cut-outs for the LEDs 142 and the substrates 141 .
- the reflective sheet 144 reflects light from the LEDs 142 , which has reached the chassis 131 side after being reflected by the bottom of the diffusion plate 132 or the like, back towards the emitting side of the LEDs 142 , for example.
- the diffusion plate 132 , the prism sheet 133 , and the lens sheet 134 are arranged so as to block the opening in the chassis 131 , and to cover the light-emitting module 140 housed inside the chassis 131 from the liquid crystal display panel 120 side.
- the diffusion sheet 132 is arranged closest to the light-emitting module 140 and directly receives light emitted by the light-emitting module 140 .
- the diffusion plate 132 is arranged such that the surface of the diffusion plate 132 where light from the light-emitting module 140 is incident is substantially parallel to the surface of the substrates 141 where the LEDs 142 are arranged.
- the diffusion plate 132 diffuses light that has been emitted from the LEDs 142 via the diffusion lenses 143 and spreads this light over the entire liquid crystal display panel 120 .
- the prism sheet 133 covers the top side of the diffusion plate 132 .
- the prism sheet 133 has triangular prisms, for example, that extend in a linear fashion in one direction and are aligned in a direction that intersects the one direction in the sheet surface.
- the prism sheet 133 deflects the radiating characteristics of light from the diffusion plate 132 .
- the lens sheet 134 covers the top side of the prism sheet 133 .
- the lens sheet 134 has spread therein micro-particles that refract and disperse light.
- the lens sheet 134 suppresses differences in brightness that lead to uneven brightness without locally condensing the light from the prism sheet 133 .
- the illumination device 130 having this type of configuration emits substantially uniform planar light in which uneven brightness has been suppressed, and illuminates the rear surface of the liquid crystal display panel 120 .
- the liquid crystal display panel 120 changes the transmittance of backlight passing through the liquid crystal on the basis of the image signal, and thus, a desired image is displayed on the display surface of the liquid crystal display panel 120 .
- the panel holders 103 are arranged on the rear surface side of the periphery of the liquid crystal display panel 120 .
- the panel holders 103 have a rectangular frame shape that fits into the front cover 101 F and an opening on the inside thereof that is similar to the front opening on the front cover 101 F.
- the liquid crystal display panel 120 is held between the panel holders 103 and the front cover 101 F.
- the light from the illumination device 130 passes through the opening in the panel holders 103 to illuminate the liquid crystal display panel 120 .
- the circuit substrates 104 are arranged on the rear surface side of the liquid crystal display device 110 .
- a plurality of the circuit substrates 104 are fixed to the rear surface of the liquid crystal display device 110 through spacers 104 a with a gap therebetween, for example.
- Each of the circuit substrates 104 functions as a power source circuit, television receiver circuit, LCD controller (controlling of the liquid crystal display panel 120 ), LED controller (controlling of the illumination device 130 ), video controller, or the like.
- the circuit substrates 104 are electrically connected to a power source plug (not shown), the liquid crystal display panel 120 , the illumination device 130 , and the like.
- the illumination device 130 includes the plurality of LEDs 142 arranged in straight rows, and the diffusion lenses 143 that extend in a bar shape in accordance with the array direction of the plurality of LEDs 142 and that are respectively shared among the plurality of LEDs 142 .
- the degree of light diffusion towards the direction forming a right angle with the array direction of the plurality of LEDs 142 is larger than the degree of light diffusion towards the array direction of the plurality of LEDs 142 (the long-side direction of the chassis 131 ).
- the illumination device 130 has one diffusion lens 143 each for diffusing light from the plurality of the respective LEDs 142 arranged in a linear row. In other words, the number of the diffusion lenses 143 to the number of the LEDs 142 can be greatly reduced in the liquid crystal display device 110 and the television receiver 100 .
- the illumination device 130 has three pairs of the plurality of LEDs 142 and the diffusion lenses 143 shared by the respective plurality of the LEDs 142 . Due to this, when it is necessary illuminate a relatively large area in the direction at a right angle to the array direction of the plurality of LEDs 142 (the short-side direction of the chassis 131 ) as with the illumination device 130 , it is possible to arrange the pairs of the plurality of LEDs 142 and the respective diffusion lenses 143 in the short-side direction of the chassis 131 .
- liquid crystal display device 110 and television receiver 100 at a low-cost and with which suitable images and the like can be displayed.
- the dimensions relating to the configuration and arrangement of the base member 2 , the diffusion cover 3 , the substrates 4 , the LEDs 5 , and the diffusion lens 6 , and the numerical values relating to the number of the LEDs 5 are not limited to the values described above, and other values may be used.
- the pairs of the plurality of LEDs 5 and the single diffusion lens 6 may be increased in accordance with the size of the radial direction of the illumination device 1 .
- the present invention can be applied to an illumination device that uses LEDs as a light source, for example.
- an illumination device that uses LEDs as a light source
- Examples of such an illumination device include ceiling lights, liquid crystal display devices, and the backlight of television receivers.
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Abstract
Description
- The present invention relates to an illumination device that uses an LED as a light source, for example. The present invention further relates to a liquid crystal display device and a television receiver provided with this illumination device.
- Fluorescent lamp illumination devices have traditionally been widely used in households, offices, and the like. Cold cathode fluorescent lamp illumination devices have also been used for liquid crystal display devices and television receivers. An ordinary fluorescent lamp such as a cold cathode fluorescent lamp is a light source in which an electrode is placed inside a glass tube where a prescribed gas has been sealed, and ultraviolet rays generated by electrical discharge are converted to visible light by hitting fluorescent material coated on the inner surface of this glass tube.
- Meanwhile, the use of LED (light-emitting diode) illumination devices has been progressing in recent years due to the possibility of light illumination at a low voltage and high efficiency. Compared to fluorescent lamps and bulbs that use filament and the like, illumination devices using LEDs as a light source make it possible to reduce power consumption. A conventional illumination apparatus, which is one example of an illumination device that uses LEDs as a light source, is disclosed in
Patent Document 1. - The illumination apparatus disclosed in
Patent Document 1 has individual LED lenses that are elliptical in a cross-sectional view respectively provided on the light illumination side of a plurality of LEDs that are in a loop shape. The long axes of the respective LED lenses face the center of this loop shape. Accordingly, this conventional illumination apparatus widely emits light towards the center and the outside of this loop shape and has a uniform brightness. - Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2012-4035
- The conventional illumination device disclosed in
Patent Document 1, however, requires a large number of LED lenses in order to evenly illuminate a wide area. This adds to the number of components and assembly steps, and leads to an increase in cost of the illumination device. There is also a risk that uneven brightness could occur between adjacent LED lenses. - Furthermore, when using a reflective sheet or the like to improve the usage efficiency of light, it is necessary to avoid the locations where the LEDs and LED lenses are attached when arranging the reflective sheet. This could decrease the workability of the installation of the reflective sheet. There are also various places where the reflective sheet is not provided, thus making it difficult to attain a large improvement in the usage efficiency of light.
- The present invention was made in view of the above-mentioned points and aims at providing an illumination device that can lower costs, improve the usage efficiency of light, and reduce uneven brightness. The present invention further aims at providing a liquid crystal display device and a television receiver provided with this illumination device.
- To solve the above-mentioned problems, an illumination device of the present invention includes a plurality of light sources arranged in a row; and a diffusion lens that is disposed on a light-emitting side of the light sources in order to diffuse light emitted by the light sources and that extends in an arrangement direction of the plurality of light sources, the diffusion lens being shared by the respective light sources, wherein a degree of light diffusion of the diffusion lens towards a right angle to the arrangement direction of the plurality of light sources is larger than the degree of light diffusion towards the array direction of the plurality of light sources.
- With this configuration, the illumination device has the single diffusion lens for diffusing the light emitted from the respective plurality of light sources. In other words, the number of diffusion lenses in relation to the number of light sources is greatly reduced. The diffusion lens is also present between the adjacent light sources. Accordingly, uneven brightness that could occur between the adjacent light sources is suppressed.
- In the illumination device having the configuration described above, the diffusion lens has a housing recess that covers and houses the light sources, and a curved surface that faces the housing recess and substantially protrudes outwards along a light-emitting direction of the light sources, and in a cross-section at a right angle to the array direction of the plurality of light sources, the curved surface has substantially arced sections that protrude outwards, the substantially arced sections being respectively formed at two spots on the left and the right of a central axis line that extends in a direction normal to an emitting surface of the light sources.
- With this configuration, the light emitted by the light sources refracts at the curved surface of the housing recess of the diffusion lens, passes through the diffusion lens, and then refracts again at the curved surface. The light is widely diffused by the curved surface via the substantially arced sections. In other words, the degree of light diffusion of the diffusion lens in the direction forming a right angle with the array direction of the plurality of light sources becomes relatively high.
- In the illumination device having the configuration described above, in the cross-section at a right angle to the array direction of the plurality of light sources, the two substantially arced sections of the curved surface both have centers of curvature at locations that are equidistant from the emitting surface of the light sources and equidistant from the central axis extending in the direction normal to the emitting surface of the light sources, the substantially arced sections having the same radius.
- With this configuration, the illumination device emits light in similar directions on both sides of the plane extending in the array direction of the plurality of light sources, in addition to the central axis (optical axis) that extends in the direction normal to the emitting surface of the light sources. Accordingly, the illumination device can uniformly illuminate the periphery of the light sources and the diffusion lens.
- In the illumination device having the configuration described above, in the cross-section at a right angle to the array direction of the plurality of light sources, the two substantially arced sections of the curved surface both have centers of curvature that are different distances from the emitting surface of the light sources and/or different distances from the central axis extending in the direction normal to the emitting surface of the light sources.
- With this configuration, the illumination device emits light in different directions on both sides of the plane extending in the array direction of the plurality of light sources, in addition to the central axis (optical axis) that extends in the direction normal to the emitting surface of the light sources. Accordingly, the differing brightness among both sides of the light sources and diffusion lens is useful at desired times.
- In the illumination device having the configuration described above, the diffusion lens has a stray light recess that is adjacent to the housing recess and that faces the curved surface, the stray light recess receding towards the curved surface.
- With this configuration, stray light that could occur due to reflection by the diffusion lens or the like is reflected by the stray light recess. Stray light reflected by the stray light recess is widely diffused via the curved surface and emitted.
- In the illumination device having the configuration described above, a diffusion cover that diffuses light exiting from the diffusion lens is disposed on a light-exiting side of the diffusion lens.
- With this configuration, the light emitted by the diffusion lens of the illumination device can be further diffused and illuminate a room, for example. Accordingly, the usage efficiency of light of the illumination device is improved.
- In the illumination device having the configuration described above, a reflective sheet that reflects light emitted by the light sources is disposed on a side of the light sources opposite to the light-emitting side, the reflective sheet facing the light-emitting side of the light sources.
- With this configuration, light from the light sources that hits the diffusion cover and reaches the side opposite to the light-emitting side of the light sources is reflected by the reflective sheet back towards the light-emitting side of the light sources, for example. Accordingly, the usage efficiency of light of the illumination device is improved. Furthermore, the number of diffusion lenses is relatively small, and thus the workability of installing the reflective sheet is improved.
- In the illumination device having the configuration described above, the plurality of light sources are arranged in a circular shape, and the diffusion lens has a ring shape.
- With this configuration, the number of the light sources and size of the diffusion lens in a circular-shaped illumination device is reduced.
- In the illumination device having the configuration described above, the plurality of light sources are arranged in a straight line, and the diffusion lens has a bar shape.
- With this configuration, the number of the light sources and size of the diffusion lens in a straight illumination device is reduced.
- In the illumination device having the configuration described above, a plurality of pairs are provided, each of the pairs having the plurality of light sources and the diffusion lens that is shared among the plurality of light sources.
- With this configuration, when it is necessary illuminate a relatively large area in the direction at a right angle to the array direction of the plurality of light sources, for example, the pairs of the plurality of light sources and the respective diffusion lenses is arranged in the direction at a right angle to the array direction of the plurality of light sources.
- The present invention includes a liquid crystal display device and a television receiver having the illumination device with the configuration described above. With this configuration, the number of diffusion lenses to the number of light sources is greatly reduced in the liquid crystal display device and the television receiver, and uneven brightness is suppressed.
- According to the present invention, an illumination device that can decrease costs, improve the usage efficiency of light, and reduce uneven brightness can be provided. By providing this illumination device, it is possible to provide a liquid crystal display device and a television receiver that can lower costs and suitably display images and the like.
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FIG. 1 is a complete perspective view of an illumination device ofEmbodiment 1 of the present invention as seen from below. -
FIG. 2 is a vertical cross-sectional view of a portion of the illumination device according toEmbodiment 1 of the present invention. -
FIG. 3 is a bottom view of the illumination device according toEmbodiment 1 of the present invention when a diffusion cover has been removed. -
FIG. 4 is a magnified bottom view of a portion of the illumination device according toEmbodiment 1 of the present invention when the diffusion cover has been removed. -
FIG. 5 is a magnified bottom view of the illumination device according toEmbodiment 1 of the present invention when the diffusion cover and diffusion lens have been removed. -
FIG. 6 is a vertical cross-sectional view where a portion of the LED and diffusion lens of the illumination device ofEmbodiment 1 of the present invention has been magnified. -
FIG. 7 is a vertical cross-sectional view where a portion of an LED and diffusion lens of the illumination device ofEmbodiment 2 of the present invention has been magnified. -
FIG. 8 is a vertical cross-sectional view where a portion of an LED and diffusion lens of the illumination device ofEmbodiment 3 of the present invention has been magnified. -
FIG. 9 is a bottom view of an illumination device according toEmbodiment 4 when a diffusion cover has been removed. -
FIG. 10 is a bottom view of an illumination device according toEmbodiment 5 when a diffusion cover has been removed. -
FIG. 11 is a front view of a television receiver according toEmbodiment 6 of the present invention. -
FIG. 12 is a horizontal top cross-sectional view of the television receiver according toEmbodiment 6 of the present invention. -
FIG. 13 is an exploded perspective view of a liquid crystal display device in the television receiver according toEmbodiment 6 of the present invention. - Embodiments of the present invention will be described below with reference to
FIGS. 1 to 13 . An illumination device (indoor illumination apparatus) ofEmbodiments 1 to 5 in which an indoor ceiling surface serves as the installation surface, and an illumination device (backlight) for use with a liquid crystal display device ofEmbodiment 6 will be described as examples. - First, the general structure of the illumination device of
Embodiment 1 of the present invention will be described usingFIGS. 1 to 3 .FIG. 1 is a complete perspective view from below the illumination device,FIG. 2 is a vertical cross-sectional view of a portion of the illumination device, andFIG. 3 is a bottom view of the illumination device when a diffusion cover has been removed. - As shown in
FIGS. 1 to 3 , anillumination device 1 has a relatively thin disk shape that completely extends along an installation surface (ceiling surface). As shown inFIGS. 2 and 3 , theillumination device 1 includes abase member 2, adiffusion cover 3,substrates 4,LEDs 5 that are the light source, adiffusion lens 6, and areflective sheet 7. - The
base member 2 is arranged above theillumination device 1 in the vicinity of the ceiling surface, which is the installation surface of theillumination device 1. Thebase member 2 has a round plate shape that faces downwards, thebase member 2 having a diameter D1 of 600 mm, for example. The inside of thebase member 2 holds thesubstrates 4 on which therespective LEDs 5 are mounted, thediffusion lens 6, and thereflective sheet 7. A power supply connector (not shown) is connected through the radial center of thebase member 2. This power supply connector supplies power to theLEDs 5. - A
projection 2 a that projects downward is disposed in the center of thebase member 2. The tip of theprojection 2 a has a diameter D2 of 200 mm, for example, and is near the inner surface center of thediffusion cover 3. A control section that has a power supply circuit, a control circuit, and the like (not shown) is disposed inside theprojection 2 a, and this control section is electrically connected to the power supply connector and theLEDs 5. - The
diffusion cover 3 is arranged on the bottom of theillumination device 1 and faces downward towards the room, which is the target for illumination of theillumination device 1. Thediffusion cover 3 has a circular shape with a diameter that is substantially the same as the outer diameter of thebase member 2. Thediffusion cover 3 fits into and is held by the periphery of thebase member 2, and covers the entire surface of thebase member 2 from below. Thediffusion cover 3 is a PMMA (polymethyl methacrylate) resin with a diffusing material mixed in, for example, but may be a PC (polycarbonate resin), a PS (polystyrene) resin, or a PP (polypropylene) resin. Thediffusion cover 3 is arranged on the light-emitting side of thediffusion lens 6 in order to diffuse light exiting thediffusion lens 6. The bottom surface of thediffusion cover 3 emits this light. - The
substrates 4 have a substantially rectangular shape in a plan view and are attached to the bottom of thebase member 2. TheLED 5 is a white LED (light-emitting diode) that emits white light, for example, and a plurality of theseLEDs 5 are mounted on the bottom surface of therespective substrates 4. The plurality ofLEDs 5 are supplied with power through the power source connector and the control section, and radiate light towards thediffusion cover 3 below. - The
diffusion lens 6 is arranged so as to cover the bottoms of therespective LEDs 5 in order to diffuse the light emitted by theLEDs 5. Thediffusion lens 6 has a single ring shape in order to completely cover the plurality ofLEDs 5. - The
reflective sheet 7 is arranged above theLEDs 5 and below thesubstrates 4. Thereflective sheet 7 is a sheet member having a substantially donut shape that covers the area from the outer radial side of theprojection 2 a of thebase member 2 to the periphery of thebase member 2. The portions corresponding to theLEDs 5 andsubstrates 4 are cut out. Thereflective sheet 7 is a white PET foam (polyethylene terephthalate), for example. Light from theLEDs 5 that hits the inner surface of thediffusion cover 3 and reaches thebase member 2 side is reflected by thereflective sheet 7 back towards the emitting side of theLEDs 5, for example. - Instead of the
reflective sheet 7, a highly reflective surface may be formed by coating a silver material or the like on the bottom surface of thebase member 2, for example, or a highly reflective surface may be formed by applying a mirror finish or the like on the bottom surface of thebase member 2. - Next, the specific configurations of the
substrates 4, theLEDs 5, and thediffusion lens 6 of theillumination device 1 will be described usingFIGS. 4 to 6 in addition toFIGS. 2 and 3 .FIG. 4 is a magnified bottom view of a portion of theillumination device 1 when thediffusion cover 3 has been removed,FIG. 5 is a magnified bottom view of theillumination device 1 when thediffusion cover 3 anddiffusion lens 6 have been removed, andFIG. 6 is a vertical cross-sectional view where a portion of theLEDs 5 and thediffusion lens 6 has been magnified. InFIGS. 4 and 5 the depiction of thereflective sheet 7 has been omitted. InFIG. 6 , the left shows the outer radial side (periphery) of theillumination device 1, and the right shows the inner radial side (center) of theillumination device 1. - As shown in
FIG. 3 , eight of thesubstrates 4 are arranged so as to form a substantially circular shape with the central axis of thecircular base member 2 as the center, or more specifically, so as to form a regular octagon, for example. As shown inFIG. 5 , the eightsubstrates 4 each hold fiveLEDs 5, for example. Approximately 40 of theLEDs 5 are arranged in a row so as to form a circular shape having the central axis of thecircular base member 2 as the center thereof. - The arrangement circle of the plurality of
LEDs 5 has a diameter D3 (seeFIG. 5 ) of 420 mm, for example. In other words, inFIG. 5 , a radial distance X from the periphery of theprojection 2 a to the periphery of thebase member 2 is 200 mm, whereas a radial distance Y from the periphery of theprojection 2 a to the arrangement circle of theLEDs 5 is 110 mm, and a radial distance Z from the arrangement circle of theLEDs 5 to the periphery of thebase member 2 is 90 mm. This results in a relation of distance Y>distance Z. - A gap L in the peripheral direction of
LEDs 5 that are adjacent, among the respective plurality of LEDs 5 (seeFIG. 5 ), is 33 mm, for example. In contrast, a distance H (seeFIG. 2 ) from thesubstrates 4 to thediffusion cover 3 is set to be 26 mm, for example. In other words, theillumination device 1 is configured such that the gap L between theadjacent LEDs 5 and the distance H from thesubstrates 4 to thediffusion cover 3 is L/H≦1.3, for example. - As shown in
FIG. 6 , thediffusion lens 6 is arranged on the light-emitting side of theLEDs 5 and completely covers theLEDs 5. Thediffusion lens 6 has a ring shape that extends in accordance with the array direction of the plurality ofLEDs 5. Thediffusion lens 6 is shared among the plurality ofLEDs 5. Thediffusion lens 6 is a PMMA (polymethyl methacrylate) resin with a diffusing material mixed in, for example, but may be a PC (polycarbonate resin), or a PS (polystyrene) resin. - The
diffusion lens 6 has ahousing recess 6 a in the top thereof. Thehousing recess 6 a has a size and shape that covers and houses all of theLEDs 5 together, and is formed in a looped trench shape, the central axis of which coincides with thediffusion lens 6. As shown inFIG. 6 , the vertical cross-section of thehousing recess 6 a, which is parallel to the radial direction thereof, has a substantially parabolic shape or a substantially “U” shape that recedes downward from the top of thediffusion lens 6. - The bottom of the
diffusion lens 6 is acurved surface 6 b disposed on the outside of the emitting direction of theLEDs 5. Thecurved surface 6 b faces thehousing recess 6 a, and as shown inFIG. 6 the vertical cross-section parallel to the radial direction substantially protrudes towards the outside of the emitting direction of theLEDs 5. Thecurved surface 6 b is formed as a looped projection, the central axis of which coincides with thediffusion lens 6. - In the vertical cross-section parallel to the radial direction (the cross-section that forms a right angle to the array direction of the LEDs 5), the
curved surface 6 b of thediffusion lens 6 has two substantially arcedsections LEDs 5. In the vertical cross-section parallel to the radial direction, the substantially arcedsections surface 5 a of theLEDs 5. The periphery of the central axis CL, which is between the substantially arcedsections curved surface 6 b, recedes towards theLEDs 5. - With this configuration, the light emitted by the
LEDs 5 refracts at the curved surface of thehousing recess 6 a of thediffusion lens 6, passes through thediffusion lens 6, and refracts again at thecurved surface 6 b. In thecurved surface 6 b, the light is widely diffused through the substantially arcedsections diffusion lens 6 in the direction forming a right angle with the array direction of the plurality of LEDs 5 (the direction parallel to the radial direction) can be made comparatively high. - As described above, the
illumination device 1 includes the plurality ofLEDs 5 arranged in a row in a circular shape, and thediffusion lens 6 that extends in a ring shape in accordance with the array direction of the plurality ofLEDs 5 and that is shared by the plurality ofLEDs 5. Thediffusion lens 6 has a degree of light diffusion in a direction (the direction parallel to the radial direction) at a right angle to the array direction of the plurality ofLEDs 5 that is high compared to the degree of light diffusion in the array direction of the plurality ofLEDs 5. With this configuration, theillumination device 1 has thesingle diffusion lens 6 for diffusing the light emitted from the plurality ofLEDs 5. In other words, the number of thediffusion lenses 6 with respect to the number of theLEDs 5 can be greatly reduced. Thediffusion lens 6 is also present between theadjacent LEDs 5. Accordingly, it is possible to suppress uneven brightness that could occur between theadjacent LEDs 5. - In the vertical cross section parallel with the radial direction, the substantially arced
section 6 c of thecurved surface 6 b has a radius R1 extending to a center of curvature CP1, which is a distance U1 from the emittingsurface 5 a of theLEDs 5 and a distance W1 from the central axis CL (optical axis) extending in the direction normal to the emittingsurface 5 a of theLEDs 5. In the vertical cross section parallel to the radial direction, the substantially arcedsection 6 d of thecurved surface 6 b has a radius R2 extending to a center of curvature CP2, which is a distance U2 from the emittingsurface 5 a of theLEDs 5 and a distance W2 from the central axis CL (optical axis) extending in the direction normal to the emittingsurface 5 a of theLEDs 5. The distance U1 is equal to the distance U2, the distance W1 is equal to the distance W1, and the radius R1 is equal to the radius R2. - In this manner, in the vertical cross section parallel to the radial direction, the two substantially arced
sections curved surface 6 b respectively have the centers of curvature CP1 and CP2 that are at the equal distances U1 and U2 from the emittingsurface 5 a of theLEDs 5 and at the equal distances W1 and W2 from the central axis CL (optical axis) extending in the direction normal to the emittingsurface 5 a of theLEDs 5. The radii R1 and R2 from the respective substantially arcedsections illumination device 1 can emit light in similar directions on both sides of the plane extending in the array direction of the plurality ofLEDs 5, in addition to the central axis CL (optical axis) that extends in the direction normal to the emittingsurface 5 a of theLEDs 5. Accordingly, theillumination device 1 can evenly illuminate the periphery of theLEDs 5 and thediffusion lens 6. - The
illumination device 1 has thediffusion cover 3 that diffuses the light emitted from thediffusion lens 6 arranged on the light-emitting side of thediffusion lens 6; therefore, the light emitted by thediffusion lens 6 can be further diffused and illuminate a room, for example. Accordingly, the usage efficiency of light of theillumination device 1 can be improved. - The
illumination device 1 also has thereflective sheet 7, which reflects light emitted by theLEDs 5, arranged on the side opposite to the light emitting side of theLEDs 5; thus, light from theLEDs 5 that hits thediffusion cover 3 and reaches the side opposite to the light-emitting side of theLEDs 5 is reflected by thereflective sheet 7 back towards the emitting side of theLEDs 5, for example. Accordingly, the usage efficiency of light of theillumination device 1 can be improved. Furthermore, there is only one of thediffusion lenses 6, and thus it is possible to improve the workability of installing thereflective sheet 7. - A plurality of
LEDs 5 are arranged in a circular shape and thediffusion lens 6 forms a ring shape, thereby making it possible to reduce the number of theLEDs 5 and the size of thediffusion lens 6 in theillumination device 1 having a circular shape. - In this manner, according to the embodiment of the present invention, the
illumination device 1 that can decrease costs, improve the usage efficiency of light, and reduce uneven brightness can be provided. - Next, an illumination device according to
Embodiment 2 of the present invention will be described with reference toFIG. 7 .FIG. 7 is a vertical cross-sectional view where a portion of an LED and diffusion lens of the illumination device have been magnified. InFIG. 7 , the left side shows the outer radial side (periphery) of the illumination device, and the right side shows the inner radial side (center) of the illumination device. InFIG. 7 , the hatching pattern showing the cross-sectional cut ends of the diffusion lens has been omitted. The basic configuration of the present embodiment is the same as that described inEmbodiment 1 with reference toFIGS. 1 to 6 , and thus, components in common withEmbodiment 1 are assigned the same reference characters, and drawings and descriptions thereof will be omitted. - In the
illumination device 1 ofEmbodiment 2, as shown inFIG. 7 the bottom of adiffusion lens 6 has acurved surface 6 e towards the outside in the emitting direction ofLEDs 5. In the vertical cross-section parallel to the radial direction (the cross-section that forms a right angle to the array direction of the LEDs 5), thecurved surface 6 e of thediffusion lens 6 has two substantially arcedsections LEDs 5. - In the vertical cross section parallel to the radial direction, the substantially arced
section 6 f of thecurved surface 6 e has a radius R3 extending to a center of curvature CP3, which is a distance U3 from the emittingsurface 5 a of theLEDs 5 and a distance W3 from a central axis CL (optical axis) extending in the direction normal to the emittingsurface 5 a of theLEDs 5. In the vertical cross section parallel to the radial direction, the substantially arcedsection 6 g of thecurved surface 6 e has a radius R4 extending to a center of curvature CP4, which is a distance U4 from the emittingsurface 5 a of theLEDs 5 and a distance W4 from the central axis CL (optical axis) extending in the direction normal to the emittingsurface 5 a of theLEDs 5. - Compared to the substantially arced
section 6 g on the inner radial side of the central axis CL (optical axis) that extends in a direction normal to the emittingsurface 5 a of theLEDs 5, the center of curvature CP3 near the substantially arcedsection 6 f on the outer radial side is slightly closer to the central axis CL and slightly more above the emittingsurface 5 a. In other words, the distance U3 and the distance U4 are different from each other, and the distance W3 and the distance W4 are different from each other. The radius R3 and the radius R4 are approximately the same. - In this manner, in the vertical cross-section parallel to the radial direction, the centers of curvature CP3 and CP4 are located at the distances U3 and U4 where the substantially arced
sections surface 5 a of theLEDs 5 and at the distances W3 and W4 where the substantially arcedsections surface 5 a of theLEDs 5. Due to this, theillumination device 1 can emit light in different directions on both sides of the plane extending in the array direction of the plurality ofLEDs 5, in addition to the central axis CL (optical axis) that extends in the direction normal to the emittingsurface 5 a of theLEDs 5. Accordingly, the differing brightness among the inner radial direction area and the outer radial direction area of theLEDs 5 anddiffusion lens 6 is useful at desired times. - In particular, in the
illumination device 1 according toEmbodiment 2, thecurved surface 6 e of thediffusion lens 6 inclines towards the outer radial side; thus, it is possible to illuminate a large area in the outer radial direction as compared to the configuration in - Furthermore, the
diffusion lens 6 is adjacent to thehousing recess 6 a and has straylight recesses 6 h in locations facing thecurved surface 6 b. Thestray light recesses 6 h recede towards thecurved surface 6 b, in a manner similar to thehousing recess 6 a, and are disposed on the inner radial side and outer radial side of thehousing recess 6 a. With this configuration, as shown by the broken arrows inFIG. 7 , stray light SL that could occur due to reflection by thediffusion lens 6 or the like is reflected by thestray light recesses 6 h. The stray light SL that reflects at thestray light recesses 6 h can be emitted by being widely diffused through thecurved surface 6 b. - Next, an illumination device according to
Embodiment 3 of the present invention will be described with reference toFIG. 8 .FIG. 8 is a vertical cross-sectional view where a portion of an LED and diffusion lens of the illumination device has been magnified. InFIG. 8 , the left side shows the outer radial side (periphery) of the illumination device, and the right side shows the inner radial side (center) of the illumination device. InFIG. 8 , the hatching pattern showing the cross-sectional cut ends of the diffusion lens has been omitted. The fundamental configuration of this embodiment is the same as Embodiments and 2, and thus, the constituting elements shared with these embodiments will be given the same reference characters, and drawings and detailed explanations thereof will be omitted. - In an
illumination device 1 ofEmbodiment 3, as shown inFIG. 8 , the bottom of adiffusion lens 6 has acurved surface 6 k on outside of the emitting direction ofLEDs 5. In the vertical cross-section parallel to the radial direction (the cross-section that forms a right angle to the array direction of the LEDs 5), thecurved surface 6 k of thediffusion lens 6 has two substantially arcedsections LED 5. - In the vertical cross section parallel to the radial direction, the substantially arced
section 6 m of thecurved surface 6 k has a radius R5 extending to a center of curvature CP5, which is a distance U5 from an emittingsurface 5 a of theLEDs 5 and a distance W5 from a central axis CL (optical axis) extending in the direction normal to the emittingsurface 5 a of theLEDs 5. In the vertical cross-section parallel to the radial direction, the substantially arcedsection 6 n of thecurved surface 6 e has a radius R6 extending to a center of curvature CP6, which is a distance U6 from the emittingsurface 5 a of theLEDs 5 and a distance W6 from the central axis CL (optical axis) extending in the direction normal to the emittingsurface 5 a of theLEDs 5. - Compared to the substantially arced
section 6 n on the inner radial side of the central axis CL (optical axis) that extends in a direction normal to the emittingsurface 5 a of theLEDs 5, the center of curvature CP5 near the substantially arcedsection 6 m on the outer radial side is slightly closer to the central axis CL and goes abovesubstrates 4 from the emittingsurface 5 a. In other words, the distance U5 and the distance U6 are different from each other, and the distance W5 and the distance W6 are different from each other. The radius R5 is longer than the radius R6. - In this manner, in the vertical cross-section parallel to the radial direction, the centers of curvature CP5 and CP6 are located at the distances U5 and U6 where the substantially arced
sections surface 5 a of theLEDs 5 and at the distances W5 and W6 where the substantially arcedsections surface 5 a of theLEDs 5. Due to this, in a manner similar toEmbodiment 2, theillumination device 1 emits light in different directions on both sides of the plane extending in the array direction of the plurality ofLEDs 5, in addition to the central axis CL (optical axis) that extends in the direction normal to the emittingsurface 5 a of theLEDs 5. Accordingly, the differing brightness among the inner radial direction area and the outer radial direction area of theLEDs 5 anddiffusion lens 6 is useful at desired times. - In particular, in the
illumination device 1 according toEmbodiment 3, thecurved surface 6 k of thediffusion lens 6 inclines further towards the outer radial side than inEmbodiment 2; thus, it is possible to illuminate a larger area in the outer radial direction as compared to the configuration inEmbodiment 2. - Next, an illumination device according to
Embodiment 4 of the present invention will be described with reference toFIG. 9 .FIG. 9 is a bottom view of the illumination device when a diffusion cover is removed. The basic configuration of the present embodiment is the same as that described inEmbodiment 1 with reference toFIGS. 1 to 6 , and thus, components in common withEmbodiment 1 are assigned the same reference characters, and drawings and descriptions thereof will be omitted. - An
illumination device 1 according toEmbodiment 4 is provided with fourdiffusion lenses 8, as shown inFIG. 9 . Thediffusion lenses 8 have an arc shape with a central angle of 90° extending in accordance with the circular array direction of a plurality of LEDs 5 (not shown inFIG. 9 ). Each of thediffusion lenses 8 covers a plurality ofLEDs 5 across two substrates and is arranged on the light-emitting side of therespective LEDs 5. Each of thediffusion lenses 8 is also used to diffuse light emitted by the respective plurality ofLEDs 5. - Even with such a configuration, the
illumination device 1 can greatly reduce the number ofdiffusion lenses 8 to the number of theLEDs 5. The dimensional accuracy of thediffusion lenses 8 can be increased by configuring thediffusion lenses 8 in an arc shape and not a ring shape. Accordingly, the usage efficiency of light can be improved. - Next, an illumination device according to
Embodiment 5 of the present invention will be described with reference toFIG. 10 .FIG. 10 is a bottom view of the illumination device when a diffusion cover is removed. The basic configuration of the present embodiment is the same as that described inEmbodiment 1 with reference toFIGS. 1 to 6 , and thus, components in common withEmbodiment 1 are assigned the same reference characters, and drawings and descriptions thereof will be omitted. - An
illumination device 1 according toEmbodiment 5 is provided with eightdiffusion lenses 9, as shown inFIG. 10 . Thediffusion lenses 9 have an arc shape with a central angle of 45° extending in accordance with the circular array direction of a plurality of LEDs 5 (not shown inFIG. 10 ). Each of thediffusion lenses 9 covers the plurality ofLEDs 5 across one substrate and is arranged on the light-emitting side of therespective LEDs 5. Each of thediffusion lenses 9 is also used to diffuse light emitted by the respective plurality ofLEDs 5. - Even with such a configuration, the
illumination device 1 can greatly reduce the number ofdiffusion lenses 9 to the number of theLEDs 5. The dimensional accuracy of thediffusion lenses 9 can be increased by configuring thediffusion lenses 9 in an arc shape and not a ring shape. Accordingly, the usage efficiency of light can be improved. - Next, a television receiver according to
Embodiment 6 of the present invention will be explained usingFIGS. 11 to 13 .FIG. 11 is a front view of the television receiver,FIG. 12 is a horizontal top cross-sectional view of the television receiver, andFIG. 13 is an exploded perspective view of a liquid crystal display device of the television receiver. - A
television receiver 100 according toEmbodiment 6 has a liquidcrystal display device 110 that uses liquid crystal for display of images and the like. As shown inFIGS. 11 and 12 , thetelevision receiver 100 has a substantially rectangular shape in a plan view that is longer in the left-and-right direction. Thetelevision receiver 100 has anexternal cover 101 that has a flat rectangular box shape. Theexternal cover 101 is horizontally long and is supported by anupright stand 102. - The
external cover 101 includes afront cover 101F and arear cover 101R. Thefront cover 101F has a so-called frame shape that has a rectangular opening on the front side thereof. Therear cover 101R fits into thefront cover 101F so as to cover the rear side of thefront cover 101F, and this forms the rectangular box-shapedexternal cover 101. Although not shown, theexternal cover 101 has a plurality of ventilation holes that penetrate the inside and outside thereof. These ventilation holes make it possible for air to flow freely between the inside and the outside of theexternal cover 101. - As shown in
FIG. 12 , the inside of theexternal cover 101 includes the liquidcrystal display device 110,panel holders 103, andcircuit substrates 104. - The liquid
crystal display device 110 is a display device that uses liquid crystal to display images and the like, and has a substantially rectangular shape in a plan view that is longer in the left-and-right direction. As shown inFIGS. 12 and 13 , the liquidcrystal display device 110 includes a liquidcrystal display panel 120 and anillumination device 130, which is the backlight unit of the liquidcrystal display panel 120. - The liquid
crystal display panel 120 includes anactive matrix substrate 121, acolor filter substrate 122, andpolarizing plates 123. Thecolor filter substrate 122 is sometimes simply referred to as an opposite substrate. - The
active matrix substrate 121 is disposed opposite to thecolor filter substrate 122 disposed on the display surface side of the liquidcrystal display panel 120. Theactive matrix substrate 121 has TFTs (thin-film transistors) made of switching elements, pixel electrodes, and common electrodes on a prescribed surface of the active matrix substrate 121 (not shown). The pixel electrodes and the common electrodes are inter-digital electrodes that form pairs. - The
active matrix substrate 121 and thecolor filter substrate 122 are respectively covered by alignment films (not shown) that have prescribed respective surfaces that orient the liquid crystal in a specific direction. - The
active matrix substrate 121 and thecolor filter substrate 122 are bonded together by a sealing member (not shown) such that the prescribed surfaces thereof face each other. Liquid crystal is sandwiched between theactive matrix substrate 121 and thecolor filter substrate 122, and is sealed in the space surrounded by the sealing member. - The
polarizing plates 123 are bonded to prescribed surfaces that are the respective opposite surfaces of theactive matrix substrate 121 and thecolor filter substrate 122 having the liquid crystal sealed therebetween. Thepolarizing plates 123 are sheets through which only light waves oscillating in a specific direction are allowed through, and the twopolarizing plates 123 are respectively bonded such that the transmission axes thereof are offset by approximately 90. - The liquid
crystal display panel 120 configured in this manner adjusts the orientation of the liquid crystal by an electric field generated between the pixel electrodes and the common electrodes in theactive matrix substrate 121 on the basis of an image signal, thus changing the transmittance of light through the liquid crystal layer. The liquidcrystal display panel 120 is of a transverse field type as described above, for example, and causes liquid crystal molecules to rotate within a plane parallel to the main substrate surface by generating an electric field parallel to the main surface of theactive matrix substrate 121. - The
illumination device 130 is a backlit unit for illuminating the liquidcrystal display panel 120 from below and for generating this illumination light. Theillumination device 130 is arranged on the rear surface side of the liquidcrystal display panel 120. As shown inFIGS. 12 and 13 , theillumination device 130 includes achassis 131, a light-emittingmodule 140, adiffusion plate 132 that is equivalent to a diffusion cover, aprism sheet 133, and alens sheet 134. - The
chassis 131 has a box shape that is substantially rectangular in a plan view with an opening on the liquidcrystal display panel 120 side (the front side of the television receiver 100). Thechassis 131 houses the light-emittingmodule 140 therein, or namely, on aninner bottom surface 131 a of thechassis 131. - The light-emitting
module 140 emits light and is housed inside thechassis 131. The light-emittingmodule 140 includessubstrates 141, a plurality ofLEDs 142 that are the light source,diffusion lenses 143, and areflective sheet 144. - The
substrates 141 have a substantially rectangular shape in a plan view that stretches along the long-side direction of thechassis 131, and are attached to theinner bottom surface 131 a of thechassis 131. Three of thesubstrates 141 are arranged substantially parallel in the short-side direction of thechassis 131. - The
LEDs 142 are white LEDs (light-emitting diodes) that emit white light, for example, and a plurality thereof are respectively mounted on the threesubstrates 141. The plurality ofLEDs 142 are arranged in a row in parallel so as to form a straight line along the long-side direction of thesubstrates 141, which are substantially rectangular in a plan view. The plurality ofLEDs 142 emit light towards therespective diffusion lenses 143 above. - Three of the
diffusion lenses 143 are respectively provided for the threesubstrates 141. Thediffusion lenses 143 are arranged so as to cover the respective front sides of theLEDs 142, which are the light-emitting sides, in order to diffuse the light emitted from theseLEDs 142. In order for therespective diffusion lenses 143 to completely cover the plurality ofLEDs 142 mounted on one of thesubstrates 141, thediffusion lenses 143 have a bar shape extending along the long-side direction of thechassis 131 and are respectively shared among the plurality ofLEDs 142. - The detailed configuration of the
diffusion lenses 143 in a vertical cross-sectional view is at a right angle to the array direction of theLEDs 142 is similar to the configurations inEmbodiments 1 to 3, and therefore, an explanation thereof will be omitted. The configuration of thediffusion lenses 143 can be adjusted such that the degree of light diffusion towards the direction forming a right angle with the array direction of the plurality of LEDs 142 (the short-side direction of the chassis 131) is larger than the degree of light diffusion towards the array direction of the plurality of LEDs 142 (the long-side direction of the chassis 131). - The
reflective sheet 144 is arranged on the rear side of theLEDs 142, which is the front side of thesubstrate 141. Thereflective sheet 144 is a sheet member that has a rectangular shape in a plan view and that covers the entire innerbottom surface 131 a of thechassis 131. Thereflective sheet 144 has cut-outs for theLEDs 142 and thesubstrates 141. Thereflective sheet 144 reflects light from theLEDs 142, which has reached thechassis 131 side after being reflected by the bottom of thediffusion plate 132 or the like, back towards the emitting side of theLEDs 142, for example. - The
diffusion plate 132, theprism sheet 133, and thelens sheet 134 are arranged so as to block the opening in thechassis 131, and to cover the light-emittingmodule 140 housed inside thechassis 131 from the liquidcrystal display panel 120 side. - Among the
diffusion plate 132, theprism sheet 133, and thelens sheet 134, thediffusion sheet 132 is arranged closest to the light-emittingmodule 140 and directly receives light emitted by the light-emittingmodule 140. Thediffusion plate 132 is arranged such that the surface of thediffusion plate 132 where light from the light-emittingmodule 140 is incident is substantially parallel to the surface of thesubstrates 141 where theLEDs 142 are arranged. Thediffusion plate 132 diffuses light that has been emitted from theLEDs 142 via thediffusion lenses 143 and spreads this light over the entire liquidcrystal display panel 120. - The
prism sheet 133 covers the top side of thediffusion plate 132. Theprism sheet 133 has triangular prisms, for example, that extend in a linear fashion in one direction and are aligned in a direction that intersects the one direction in the sheet surface. Theprism sheet 133 deflects the radiating characteristics of light from thediffusion plate 132. - The
lens sheet 134 covers the top side of theprism sheet 133. Thelens sheet 134 has spread therein micro-particles that refract and disperse light. Thelens sheet 134 suppresses differences in brightness that lead to uneven brightness without locally condensing the light from theprism sheet 133. - The
illumination device 130 having this type of configuration emits substantially uniform planar light in which uneven brightness has been suppressed, and illuminates the rear surface of the liquidcrystal display panel 120. The liquidcrystal display panel 120 changes the transmittance of backlight passing through the liquid crystal on the basis of the image signal, and thus, a desired image is displayed on the display surface of the liquidcrystal display panel 120. - As shown in
FIG. 12 , thepanel holders 103 are arranged on the rear surface side of the periphery of the liquidcrystal display panel 120. Thepanel holders 103 have a rectangular frame shape that fits into thefront cover 101F and an opening on the inside thereof that is similar to the front opening on thefront cover 101F. The liquidcrystal display panel 120 is held between thepanel holders 103 and thefront cover 101F. The light from theillumination device 130 passes through the opening in thepanel holders 103 to illuminate the liquidcrystal display panel 120. - As shown in
FIG. 12 , thecircuit substrates 104 are arranged on the rear surface side of the liquidcrystal display device 110. A plurality of thecircuit substrates 104 are fixed to the rear surface of the liquidcrystal display device 110 throughspacers 104 a with a gap therebetween, for example. Each of thecircuit substrates 104 functions as a power source circuit, television receiver circuit, LCD controller (controlling of the liquid crystal display panel 120), LED controller (controlling of the illumination device 130), video controller, or the like. Thecircuit substrates 104 are electrically connected to a power source plug (not shown), the liquidcrystal display panel 120, theillumination device 130, and the like. - As described above, the
illumination device 130 includes the plurality ofLEDs 142 arranged in straight rows, and thediffusion lenses 143 that extend in a bar shape in accordance with the array direction of the plurality ofLEDs 142 and that are respectively shared among the plurality ofLEDs 142. With respect to thediffusion lenses 143, the degree of light diffusion towards the direction forming a right angle with the array direction of the plurality of LEDs 142 (the short-side direction of the chassis 131) is larger than the degree of light diffusion towards the array direction of the plurality of LEDs 142 (the long-side direction of the chassis 131). With this configuration, theillumination device 130 has onediffusion lens 143 each for diffusing light from the plurality of therespective LEDs 142 arranged in a linear row. In other words, the number of thediffusion lenses 143 to the number of theLEDs 142 can be greatly reduced in the liquidcrystal display device 110 and thetelevision receiver 100. - The
illumination device 130 has three pairs of the plurality ofLEDs 142 and thediffusion lenses 143 shared by the respective plurality of theLEDs 142. Due to this, when it is necessary illuminate a relatively large area in the direction at a right angle to the array direction of the plurality of LEDs 142 (the short-side direction of the chassis 131) as with theillumination device 130, it is possible to arrange the pairs of the plurality ofLEDs 142 and therespective diffusion lenses 143 in the short-side direction of thechassis 131. - In this manner, according to the configurations of the above-mentioned embodiments of the present invention, it is possible to provide the liquid
crystal display device 110 andtelevision receiver 100 at a low-cost and with which suitable images and the like can be displayed. - Embodiments of the present invention were described above, but the scope of the present invention is not limited thereto, and can be implemented with various modifications without departing from the spirit thereof.
- The dimensions relating to the configuration and arrangement of the
base member 2, thediffusion cover 3, thesubstrates 4, theLEDs 5, and thediffusion lens 6, and the numerical values relating to the number of theLEDs 5 are not limited to the values described above, and other values may be used. - In the
illumination device 1 inEmbodiment 1, the pairs of the plurality ofLEDs 5 and thesingle diffusion lens 6 may be increased in accordance with the size of the radial direction of theillumination device 1. In this case, it is preferable that the added pairs of the plurality ofLEDs 5 and thesingle diffusion lens 6 be arranged on the outer radial side in accordance with the already arranged pairs of the plurality ofLEDs 5 and thesingle diffusion lens 6. - The present invention can be applied to an illumination device that uses LEDs as a light source, for example. Examples of such an illumination device include ceiling lights, liquid crystal display devices, and the backlight of television receivers.
-
-
- 1 illumination device
- 2 base member
- 3 diffusion cover
- 4 substrate
- 5 LED (light source)
- 6 diffusion lens
- 6 a housing recess
- 6 b, 6 e, 6 k curved surface
- 6 c, 6 d, 6 f, 6 g, 6 m, 6 n substantially arced section
- 6 h stray light recess
- 7 reflective sheet
- 8, 9 diffusion lens
- 100 television receiver
- 110 liquid crystal display device
- 120 liquid crystal display panel
- 130 illumination device
- 131 chassis
- 132 diffusion plate (diffusion cover)
- 140 light-emitting module
- 141 substrate
- 142 LED (light source)
- 143 diffusion lens
- 144 reflective sheet
Claims (12)
Applications Claiming Priority (3)
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JP2012-020126 | 2012-02-01 | ||
JP2012020126 | 2012-02-01 | ||
PCT/JP2013/051950 WO2013115200A1 (en) | 2012-02-01 | 2013-01-30 | Illumination apparatus, and liquid crystal display apparatus and television receiver apparatus provided with same |
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US20150042891A1 true US20150042891A1 (en) | 2015-02-12 |
US9541259B2 US9541259B2 (en) | 2017-01-10 |
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US14/375,216 Expired - Fee Related US9541259B2 (en) | 2012-02-01 | 2013-01-30 | Illumination apparatus, and liquid crystal display apparatus and television receiver apparatus provided with same |
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US (1) | US9541259B2 (en) |
WO (1) | WO2013115200A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150219287A1 (en) * | 2014-02-06 | 2015-08-06 | Appalachian Lighting Systems, Inc. | Led light emitting apparatus having both reflected and diffused subassemblies |
CN105508942A (en) * | 2016-01-21 | 2016-04-20 | 佛山电器照明股份有限公司 | Lens used for lighting device with arc-shaped lampshade and lighting device |
US20200174318A1 (en) * | 2018-11-29 | 2020-06-04 | Molex, Llc | Light diffusing lens for light emitting device |
US20200355345A1 (en) * | 2019-04-23 | 2020-11-12 | Fusion Optix, Inc. | Optical Arrangement for Targeted Illumination Patterns From Luminaires |
Families Citing this family (1)
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JP6304538B2 (en) * | 2014-03-28 | 2018-04-04 | パナソニックIpマネジメント株式会社 | lighting equipment |
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US20120105764A1 (en) * | 2009-06-15 | 2012-05-03 | Sharp Kabushiki Kaisha | Light source unit, lighting device, display device, television receiver, and method of manufacturing reflection sheet for light source unit |
US8876311B2 (en) * | 2011-04-28 | 2014-11-04 | Panasonic Corporation | Light emitting device and illumination apparatus including same |
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JP5213383B2 (en) | 2007-08-09 | 2013-06-19 | シャープ株式会社 | LIGHT EMITTING DEVICE AND LIGHTING DEVICE EQUIPPED WITH THE SAME |
JP2010165477A (en) | 2009-01-13 | 2010-07-29 | Ccs Inc | Light irradiation device |
JP2011014831A (en) | 2009-07-06 | 2011-01-20 | Panasonic Corp | Light emitting device, surface light source, and liquid crystal display device |
JP2012004035A (en) | 2010-06-18 | 2012-01-05 | Panasonic Electric Works Co Ltd | Lighting fixture |
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2013
- 2013-01-30 US US14/375,216 patent/US9541259B2/en not_active Expired - Fee Related
- 2013-01-30 WO PCT/JP2013/051950 patent/WO2013115200A1/en active Application Filing
Patent Citations (2)
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US20120105764A1 (en) * | 2009-06-15 | 2012-05-03 | Sharp Kabushiki Kaisha | Light source unit, lighting device, display device, television receiver, and method of manufacturing reflection sheet for light source unit |
US8876311B2 (en) * | 2011-04-28 | 2014-11-04 | Panasonic Corporation | Light emitting device and illumination apparatus including same |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150219287A1 (en) * | 2014-02-06 | 2015-08-06 | Appalachian Lighting Systems, Inc. | Led light emitting apparatus having both reflected and diffused subassemblies |
US9903540B2 (en) * | 2014-02-06 | 2018-02-27 | Appalachian Lighting Systems, Inc. | LED light emitting apparatus having both reflected and diffused subassemblies |
CN105508942A (en) * | 2016-01-21 | 2016-04-20 | 佛山电器照明股份有限公司 | Lens used for lighting device with arc-shaped lampshade and lighting device |
US20200174318A1 (en) * | 2018-11-29 | 2020-06-04 | Molex, Llc | Light diffusing lens for light emitting device |
US10852585B2 (en) * | 2018-11-29 | 2020-12-01 | Molex, Llc | Light diffusing lens for light emitting device |
US20200355345A1 (en) * | 2019-04-23 | 2020-11-12 | Fusion Optix, Inc. | Optical Arrangement for Targeted Illumination Patterns From Luminaires |
US20220364708A1 (en) * | 2019-04-23 | 2022-11-17 | Fusion Optix, Inc. | Lighting Arrangements for Targeted Illumination Patterns |
US11592158B2 (en) * | 2019-04-23 | 2023-02-28 | Fusion Optix, Inc. | Lighting arrangement with optical composite for targeted illumination patterns |
US11719413B2 (en) * | 2019-04-23 | 2023-08-08 | Fusion Optix, Inc. | Lighting arrangements for targeted illumination patterns |
Also Published As
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WO2013115200A1 (en) | 2013-08-08 |
US9541259B2 (en) | 2017-01-10 |
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